BS PD ISO/TR 21245-2:2016 aims to identify basic conditions of rail projects, which are essential input for thedesign of rail systems. This document does not interfere with existing national and local laws, legalrequirements and regulations. It considers only the "planning stage" of rail projects and does not dealwith the "execution stage". Any type of rail projects is intended to be dealt with, such as building a newline, retrofitting or upgrading of existing lines and change of operation or maintenance.
In this document, conditions are dealt with as premises or constraints, which can be difficult to adjustor change by stakeholders concerned in the project.